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black marks. These are in fact a corneous head, six jointed legs, and a dorsal 

 and ventral series of plates. I immediately recognised the head and legs as 

 identical with those of the little black mite already described, but presenting 

 a ludicrous appearance in being widely separated from each other by the white 

 skin of the larva. I have no doubt that the dorsal and ventral series of black 

 marks are the corresponding plates of the mite-like larva floated away from 

 each other by the expansion of the intervening membrane. By measure- 

 ment also thty agree exactly in size, although the larva extracted from the 

 wasp-grub is ten times the length and six times the width of the little Mcloe- 

 like larva. In length it is J inch (4'5 millim.), and l-28th in breadth. Except 

 that its spiracles are not open, its respiratory and digestive systems look just 

 like those of the externally feeding larva. The head (first segment) (Figs. 

 D. E. 1. ,) is black and triangular, with a pair of antennae situated near its pos- 

 terior lateral angles : these ate three-jointed ; the first joint is short, and 

 supports a bristle beside the long second joint, the last joint being a long 

 pointed seta. In front and above the base of each antenna is a pair (possibly 

 more) of white eye-spots. The mouth and under part of the head are difficult 

 to make out. There are a pair of strong jaws (Fig. G.), each shaped like a 

 comma, with a large globular base and a sharp-pointed extremity. There are 

 two four-jointed palpi, which seem to arise each from the front of a large rectan- 

 gular piece, which is probably the maxilla. The legs (Figs. E. 2, 3, 4, and F. ) 

 still retain the sucker-disks at their extremities ; they have very thick femora 

 and narrow tibia?*. The dorsal plates are twelve in number (making with the 

 head thirteen segments) (Fig. D.) ; the first is of oval outline, flattened in 

 front, and has two short bristles at its posterior angles ; the second and third 

 are larger, and have each a small subsidiary triangular piece at the anterior 

 lateral corners ; each has a bristle at the posterior angles ; the fourth, fifth, 

 sixth, seventh, eighth, ninth, and tenth are narrow, transverse, ribbon-like 

 pieces, the anterior ones straight, the posterior ones curved ; and each has 

 a bristle at its outer end, and a secondary piece at each extremity, which 

 also carries a small bristle.: the fifth is the longest ; and they become gradually 

 shorter to the eleventh, which is a short quadrangular piece with a mere 

 indication of bristles ; the twelfth is triangular, with a long seta springing 

 from below each side. The first ventral piece (Fig. E. 2, &c.) is nearly square, 

 except that it is rounded behind and much hollowed out in front ; the second 

 is less so ; the third is narrow antero-posterioily, but of the same breadth ; 

 each of these has a strong spine closely adpressed and directed backwards near 

 each anterior angle ; the fourth to the tenth are narrow transverse pieces, 

 slightly arched, with the convexity forwards, and each smaller than the previous 

 one, and each with three bristles on either side near its posterior edge ; the 

 eleventh is oval, with two rather longer bristles at the sides, and two shorter 



* A careful examination of a prepared specimen of the suckers shows them to be ap- 

 pendages of a three-jointed tarsus, in addition to which there are one or two claws (spurs 

 at the extremity of the tibia ?). 



